Integrative Health
This Fitness Metric May Be The Most Overlooked Predictor Of Heart Disease
Author:Zhané SlambeeAugust 11, 2026
mindbodygreen editor
By Zhané Slambee
Image by Natalia Blauth / Unsplash
August 11, 2026
Most people track their weight, blood pressure, maybe cholesterol. But there’s another number that researchers say may tell you even more about your heart health, and most of us have never thought to check it
Cardiorespiratory fitness (CRF) is a measure of how well your heart, lungs, and muscles work together when you’re moving, and VO₂ max, the maximum amount of oxygen your body can use during exercise, is the most common way to measure it
A new umbrella review1 looked at whether CRF can do more than just reflect how fit you are. The question: can it actually help identify who already has cardiovascular disease, or predict who’s at risk for a serious cardiac event?
About the study
Higher CRF has long been linked to better heart health. The American Heart Association has even recommended it be treated as a standard clinical measurement, like blood pressure or cholesterol
But researchers wanted to know something more specific: can CRF actually be used to detect heart disease in someone who already has it, or predict who’s likely to develop a serious cardiac event down the line?
To find out, they pulled together findings from six large research reviews covering more than 31,000 people. Most of the reviews looked at heart health outcomes across different populations
One focused on mitochondrial disorders, conditions where the body’s cells struggle to produce energy properly
What the data showed across populations
The results varied depending on who was being studied, but the overall picture was consistent: fitness level is a meaningful signal for heart health
In people with heart failure, CRF was a strong predictor of serious cardiac events, things like sudden cardiac death or needing a heart transplant. In women being evaluated for blocked arteries, CRF showed high accuracy as a diagnostic tool
For people with type 2 diabetes, the accuracy was lower, likely because heart disease in that group is more complex and harder to detect with a single measure
CRF also showed the ability to flag cardiovascular risk in otherwise healthy kids and teens, a notable finding, since fitness is rarely discussed as a health marker in children
The standout result: CRF was highly accurate at detecting mitochondrial disorders (conditions where cells can’t produce energy properly) in adults. This was the only finding in the entire review rated with high certainty
One important caveat: the quality of the underlying research was rated low across the board, and the confidence in results varied widely by outcome
The findings are most reliable for people who already have a health condition. For healthy adults, the picture is less clear
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How to use this information
You don’t need a lab test to start paying attention to your cardiorespiratory fitness. Many fitness trackers and smartwatches now estimate VO₂ max using heart rate data during exercise, and some offer a resting estimate based on age and basic health metrics
These aren’t perfectly precise, but they’re useful for tracking trends over time
To actually improve your CRF, the most effective strategies are also the most accessible:
- Consistent aerobic exercise: brisk walking, running, cycling, or swimming done regularly builds your aerobic base over time.
- Zone 2 cardio: a conversational, moderate-intensity pace you can sustain for 30 to 45 minutes is one of the most efficient ways to improve CRF.
- Interval training: adding one or two higher-intensity sessions per week can accelerate gains without requiring hours of extra effort.
Consider tracking your CRF alongside other standard health markers like blood pressure and cholesterol
It won’t replace those numbers, but it adds a dimension of health information they can’t capture on their own
The takeaway
Cardiorespiratory fitness has long been framed as a performance goal, but a growing body of evidence increasingly positions it as a meaningful clinical signal, one that may reveal cardiovascular risk before other standard markers do
The research is most reliable for people with existing conditions, and the overall evidence base still has room to grow. For now, the clearest message is that improving your CRF pays dividends well beyond what the scale or a blood pressure cuff can show
